摘要: - does the rainy season usually last in your country? -More than two months. A. When B. How long C. How often D. How soon

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Every time you turn on the television or take a ride in a car ,you could be adding to a problem called acid rain(酸雨). In this article, you’ll learn how acid is created, and how it affects us, and more importantly, what we all can do to prevent it.
How is acid rain created?
When people use fuels(燃料), such as coal and gasoline, poisonous gases are give off. When these gases mix with rain, acid rain forms. Many power stations burn fuels in order to creat the electricity(电) that we use in our homes and offices every day. Cars and trucks also send these gases into the air when they burn gasoline .When rain mixes with these gases, harmful things called acids form. This is acid rain.
How does acid rain affect us?
Acid rain damages(毁坏)everything that it touches. It poisons our rivers, ponds, lakes, and oceans along with all the life in them. It pollutes our soil and crops, harms trees, and can even kill fish and plants. Acid rain also eats away at buildings.
How can we prevent acid rain?
We need to cut down on the pollution that gets into our air. Turn off lights, television, and other electrical appliances if you are not using them, Walk or take a bike whenever possible. If you are travelling a long distance, take a bus or train to save fuel.
As research shows, acid rain harms our environment. But people everywhere can take small steps now to help protect our environment for future generations.
【小题1】When power stations burn fuel,_______.

A.acid rain formB.air pollution is caused
C.noise pollution is causedD.acid rain gets heavier
【小题2】 According to the article, acid rain affects us _______.
A.suddenlyB.slightlyC.seriouslyD.immediately
【小题3】 What advice does the article give us?
A.Go to school on foot or by bike if we can.
B.Go to bed earlier in order to use less electricity.
C.Travel by bus to prevent acid rain.
D.Turn off the television on rainy days.
【小题4】 What is the best title of the article?
A.Preventing Acid RainB.Forming of Acid Rain
C.Acid rain, Heavy RainD.Acid Rain, Killer Rain

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Spring is a good season to fly kites. You can fly your kites in the park, in the field or on the play ground. There are many different kinds of kites. Some look like birds; Some look like planes and some look like butterflies. People often fly kites on a sunny and windy day. And the best month for flying kites is March. How can we fly our kites in the sky. First, we run with our kites against the wind. Then when the kite can fly in the sky, you can just stay there with your string reel(线轴) in your hand. When the kite doesn’t fly in the sky, just adjust(调整) the string reel. The string on the reel must be very strong. If you want to fly kites very well, you should practice it more with your friends. Maybe you feel a little difficult at first, but if you fly kites often you will find it very easy and interesting. Flying kites is a very good activity in spring, and a lot of people like it.

1.Where can’t you fly your kites?

A.In the park.

B.In the field.

C.In the street.

D.On the playground.

2.When do people often fly kites?

A.On a cold day.

B.On a rainy day.

C.On a cloudy day.

D.On a sunny and windy day.

3.If the kite can’t fly well in the sky, what should we do?

A.Run quickly.

B.Adjust the string reel

C.Run against the wind.

D.Stay where you are.

4.What does the underlined word “against” mean?

A.反抗

B.碰撞

C.逆着

D.对立

5.Flying kites is a good sports in         .

A.spring

B.summer

C.autumn

D.winter

 

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When the traffic lights turn red, we will stop driving a car or crossing a street. Why is red used for traffic lights instead of other colors?
As we know, scattering(散射) happens when light goes through the air. For the same media(媒质), if the wavelength islong, the scattering will be short. If the wavelength is short, then the scattering will be long.
Of all lights we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.
Using the red light can help drivers in farther areas sec the lights. It helps drivers stow down or stop in lime. If drivers don't see the red light until they are close, they may not be able to stop the car in time. An accident may happen Red can also excite people. We can act more quickly when we see the color red. In a word, red lights help drivers stop in time and help prevent accidents.
【小题1】 When the traffic lights turn ______, we will stop driving a car.
A. red    B green     C. yellow
【小题2】According to the passage, the scattering of the red light is the _______.
A. longest    b. weakest       C. farthest
【小题3】 The underlined word "wavelength" means________ in Chinese.
A.波浪        B.光波      C.波长
【小题4】 What can the red light help drivers do?
A. It can help drivers in farther areas see the lights.
b. It can help drivers slow down or stop in time.
C.A and b
【小题5】Which of the following is the best title?
A. Why do accidents happen
b. How does the red light travel
C. Why do we use red traffic lights
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When the traffic lights turn red, we will stop driving a car or crossing a street. Why is red used for traffic lights instead of other colors?

As we know, scattering (散射) happens when light goes through the air. For the same media(媒质), if the wavelength is long, the scattering will be short. If the wavelength is short, then the scattering will be long.

Of all lights we can see red has the longest wavelength, so the scattering is the weakest. That means the red light travels far. In fact, it travels farther on rainy days.

Using the red light can help drivers in farther areas sec the lights. It helps drivers stow down or stop in lime. If drivers don't see the red light until they are close, they may not be able to stop the car in time. An accident may happen Red can also excite people. We can act more quickly when we see the color red. In a word, red lights help drivers stop in time and help prevent accidents.

1. When the traffic lights turn ______, we will stop driving a car.

A. red    B green     C. yellow

2.According to the passage, the scattering of the red light is the _______.

A. longest    b. weakest       C. farthest

3. The underlined word "wavelength" means________ in Chinese.

A.波浪        B.光波      C.波长

4. What can the red light help drivers do?

A. It can help drivers in farther areas see the lights.

b. It can help drivers slow down or stop in time.

C. A and b

5.Which of the following is the best title?

A. Why do accidents happen

b. How does the red light travel

C. Why do we use red traffic lights

 

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